Solenoids are sometimes used in "wet" interior environments within certain devices. Yet the electrical connections to the solenoids must be made exterior of the "wet" environments. In some of these devices the interior environments contain pressurized fluid whose leakage to the exterior must be prevented. One example of such a device is a high-pressure fuel injector that is used to inject fuel directly into a combustion chamber of an internal combustion engine. Such an injector may experience internal pressures as high as about 2,000 psi. The solenoid coil must be constructed to withstand the rigors of such usage by continuing to operate properly over its lifetime, and it must also remain sealed with respect to the injector body so that fuel does not leak past the solenoid coil to the exterior of the injector. Typically, these requirements are met by encapsulation of the solenoid coil in a suitable encapsulant material. Attainment of proper sealing requires strict compliance with both surface finish and dimensional control for the involved sealing surfaces, and as pressures become larger, surface finish and dimensional control become more important.
The present invention relates to a new and unique, and cost-effective, method of making an encapsulated solenoid coil that will exhibit those characteristics necessary for high pressure usage. The specific methodology will be disclosed in the ensuing description which is accompanied by drawings. The disclosure presents a presently preferred embodiment in accordance with the best mode contemplated at the present time for carrying out the invention. Additional features and advantages may also be perceived by the reader as the disclosure proceeds.